Any geologists in the house?

[AHPP]

The council has spent a fortune not far from me, trying to stop a spring from welling up in the middle of a lane. Despite three attempts and a lot of civil engineering, the spring is now welling up 10' below their last attempt.

I would save your customer a lot of money, and plant a bog garden in the wet places.

 

I agree. Man plans, god laughs. You can't beat nature. Plant a few mini patches of Alder (the Alder in Aldershot) and make up a good story for them.

[drinksloe]

If it is a natural spring u will have trouble.

 

Are all the wet spots in the same area, roughly.

I'd stick some garden canes in all the places he can remember them see if there is any pattern, then have a walk about with some bent fencing wire see if they pick up anything uphill from them.

If u found where the spring was u could mibee pipe/drain it directly from there into an existing field drain or something.

Or the other option lay a boundry drain right round outside or where u expect water coming from, but that won't work if water coming up from the ground

[treesrus]

i've come accross similar, over limestone terrace - clints and grykes - like sinkholes in limestone that have over years filled with topsoil.

[Cae Ffynnon]

Are the wetspots in a line following a contour? That would indicate ground water, spring line. Do they move up and down the slope with the seasons, ground water levels increse in winter and drop in summer.

Any chance these are old mine workings of some sort that have been backfilled?

If a new occurence has anything changed above the site to redirect water, or below to cause ponding? Any ponds or reservoirs been constructed downslope?

Dowising is worth a try, it is more reliable than the electronic gizmos, to try and locate any pipes, field drainage etc. Dig a couple of trial pits, one in a wet bit, see whats there. One in the natural, have a look. Then fill with water and time how long they take to drain. Will give you an idea on porosity of the ground.

Quick thoughts, over a brew.

 

Chris

[daltontrees]

A client has a lawn that`s on quite a steep hill which is predominantly hard ground that is high and dry. There are several wet spots of around a metre square that are so soft you could end up waist deep if you stood there long enough, unless he drives his mower over these area`s flat out he ends up digging it out. I need to engineer a solution so am looking for ideas, has anyone here had any experience of this? clock the vid.

 

Bob

 

 

 

Give me a grid reference (8 figure) and I will look up the geology and soils. Waste of time speculating what it can be unless the default solid/drift characteristics of the locale are known.

 

You can use this Grid Reference Finder

[Wendelspanswick]

The BGS (British Geological Survey) website is really useful in instances like this, have a look at the Geological map as well as the Bore Hole Records.

Geology of Britain viewer | British Geological Survey (BGS)

[matelot]

tbh, it look well weird.

 

I work in road construction. I remember once we were drilling test holes and we struck an artesian well (google it). We had a hollow drill shaft sticking 2m out the ground and water was pouring out the end of it. If you have a length of old copper pipe stick it in and see if water comes out the top.

 

Is there a local university? If there is send the video to their civil engineering department and ask them what it is. I can't see replacing the soft spots with hardcore making much difference (as you say).

 

A proper solution would involve drainage.

[difflock]

Hold me back Bob!

Cos ah love drains,

Looks like Springs, also looks like running sand, which is to say sand(of a particular grading) suspended in/by water.

Water MUST be rising, ERGO intercept the source i.e. "go deep" and solve the problem.

But it would be useful to know the area & disposition of the wet spots.

And yes "tramping" about with machinery is generally enough to disturb the soil structure such that the water very soon erupts elsewhere.

The drains will almost certainly need Geotextile filter membrane to prevent the running sand infiltrating and blocking the pipes.

Would LGP Eddie not have useful input?

Cheers

M

[Lazurus]

Plant willows?

[eggsarascal]

Hold me back Bob!

Cos ah love drains,

Looks like Springs, also looks like running sand, which is to say sand(of a particular grading) suspended in/by water.

Water MUST be rising, ERGO intercept the source i.e. "go deep" and solve the problem.

But it would be useful to know the area & disposition of the wet spots.

And yes "tramping" about with machinery is generally enough to disturb the soil structure such that the water very soon erupts elsewhere.

The drains will almost certainly need Geotextile filter membrane to prevent the running sand infiltrating and blocking the pipes.

Would LGP Eddie not have useful input?

Cheers

M

 

Sounds like a good call to me, although the second pile of spoil in the video does look like pumped shite that as come from a broken sewage rising main, but Bob ruled out any pipe work or septic tank yesterday.

 

If it is on running sand its a right bugger to work with, we hit running sand in Norfolk whilst laying a new sewage network ia few years ago. It didn't half drag the job out.

 

 

Looking at the map on the link below doesn't show much, if and running sand in Bob's area, assuming the job is in Bob's neck of the woods.

 

Running sand | GeoSure | British Geological Survey (BGS)